Repeat Exercise 20.14, adding a check in T1 so that does not exceed 90. Reference E...

Repeat Exercise 20.14, adding a check in T₁ so that does not exceed 90.

Reference Exercise 20.14

Change transaction T2 in Figure 20.2(b) to read

read_item(X);

X := X + M;

if X > 90 then exit

else write_item(X);

Discuss the final result of the different schedules in Figures 20.3(a) and (b), where M = 2 and N = 2, with respect to the following questions: Does adding the above condition change the final outcome? Does the outcome obey the implied consistency rule (that the capacity of X is 90)?